JP6774841B2 - Composite semipermeable membrane and spiral separation membrane element - Google Patents

Description

The present invention relates to a composite semipermeable membrane and a spiral separation membrane element. Such a composite semipermeable membrane and a spiral type separation membrane element are suitable for the production of ultrapure water, desalination of brackish water or seawater, and from stains that cause pollution such as dyed wastewater and electrodeposition paint wastewater. , It is possible to remove and recover the pollution source or active substance contained in it and contribute to the closure of wastewater. In addition, it can be used for advanced treatment such as concentration of active ingredients in food applications and removal of harmful components in water purification and sewage applications. It can also be used for wastewater treatment in oil fields and shale gas fields.

Composite semipermeable membranes are called RO (reverse osmosis) membranes, NF (nanofiltration) membranes, and FO (forward osmosis) membranes depending on their filtration performance and treatment method. Ultrapure water production, seawater desalination, and desalination of brackish water. It can be used for salt treatment, wastewater reuse treatment, etc.

As a composite semipermeable membrane used industrially, for example, a composite semipermeable membrane in which a thin film layer containing a crosslinked polyamide obtained by polycondensing a polyfunctional acid halide and a polyfunctional amine component is formed on a support membrane. Has been proposed (Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-237230

The conventional composite semipermeable membrane has insufficient water permeability. Then, when the water permeability is improved, there is a trade-off problem that the blocking performance of the ionic substance and / or the nonionic substance is lowered.

The present invention is a composite semipermeable membrane in which the three performances of blocking performance of an ionic substance, blocking performance of a nonionic substance, and water permeability are excellent in a practically well-balanced manner, and a spiral type separation including the composite semipermeable membrane. It is an object of the present invention to provide a membrane element.

As a result of diligent studies to solve the above problems, the present inventors have found that the above object can be achieved by the composite semipermeable membrane shown below, and have completed the present invention.

That is, the present invention relates to a composite semipermeable membrane in which a skin layer containing a polyamide resin is formed on the surface of a porous support.
The polyamide-based resin is obtained by polymerizing a polyfunctional acid halide component and a polyfunctional amine component, and the polyfunctional amine component is m-phenylenediamine and at least one of the following general formulas (1). Including the diamine compound represented by
The ratio (mol%) of the segment (A) derived from m-phenylenediamine to the segment (B) derived from the diamine compound in the polyamide resin is 99.9: 0.1 to 98: 2 ( Segment (A): A composite semipermeable membrane, characterized in that it is a segment (B)).


(In the formula, either R ¹ or R ² is COOH and the other is hydrogen, and R ³ and R ⁴ are independently hydrogen or alkyl groups having 1 to 4 carbon atoms, respectively.)

Further, the present invention relates to a composite semipermeable membrane in which a skin layer containing a polyamide resin is formed on the surface of a porous support.
The polyamide resin is obtained by polymerizing a polyfunctional acid halide component and a polyfunctional amine component, and the polyfunctional amine component is m-phenylenediamine and at least one of the following general formulas (2). Including the diamine compound represented by
The ratio (mol%) of the segment (A) derived from m-phenylenediamine to the segment (C) derived from the diamine compound in the polyamide resin is 97: 3 to 83:17 (segment (A)). : A composite semipermeable membrane, characterized in that it is a segment (C)).


(In the formula, either R ⁵ or R ⁶ is COOR ⁹ and the other is hydrogen, R ⁹ is an alkyl group having 1 to 4 carbon atoms, and R ⁷ and R ⁸ are independently hydrogen. Or it is an alkyl group having 1 to 4 carbon atoms.)

The present inventors have a segment (A) derived from m-phenylenediamine and a segment (B) derived from a diamine compound represented by the general formula (1) or a diamine represented by the general formula (2). By forming a skin layer using a polyamide resin containing a segment (C) derived from a compound in a specific ratio, there are three performances: blocking performance of ionic substances, blocking performance of nonionic substances, and water permeability. We have found that a composite semipermeable membrane with excellent performance in a well-balanced manner can be obtained. The reason why such an effect is obtained is not clear, but it is generally known that the use of a highly reactive monomer tends to reduce the crosslink density of the skin layer, but the above general formula (1) Alternatively, the diamine compound represented by (2) is less reactive than m-phenylenediamine and has a hydrophilic substituent, so that the skin does not reduce the crosslink density of the skin layer. It is considered that the hydrophilicity of the layer was improved.

When the ratio (mol%) of the segment (B) derived from the diamine compound represented by the general formula (1) is less than 0.1, the water permeability of the composite semipermeable membrane becomes insufficient. It is considered that the reason is that the content of the hydrophilic substituent in the polyamide resin is small. On the other hand, when the ratio (mol%) of the segment (B) exceeds 2, the blocking performance of the ionic substance and / or the nonionic substance of the composite semipermeable membrane is deteriorated. It is considered that the reason is that the content of the hydrophilic substituent in the polyamide resin is high, but the three-dimensional structure of the polyamide resin becomes coarse due to the steric hindrance of the hydrophilic substituent.

Further, when the ratio (mol%) of the segment (C) derived from the diamine compound represented by the general formula (2) is less than 3, the water permeability of the composite semipermeable membrane is improved for the same reason as described above. Will be inadequate. On the other hand, when the ratio (mol%) of the segment (C) exceeds 17, the blocking performance of the ionic substance and / or the nonionic substance of the composite semipermeable membrane deteriorates for the same reason as described above.

In the polyamide resin, when the amount of segments derived from all polyfunctional amine components is 100 mol%, the total amount of the segment (A) and the segment (B) is 50 mol% or more. Is preferable. When the total amount of the segment (A) and the segment (B) is 50 mol% or more, the effect of the present invention is further improved.

Further, in the polyamide resin, when the amount of segments derived from all polyfunctional amine components is 100 mol%, the total amount of the segments (A) and the segments (C) is 50 mol% or more. It is preferable to have. When the total amount of the segment (A) and the segment (C) is 50 mol% or more, the effect of the present invention is further improved.

In the polyamide resin, when the amount of segments derived from all the monomer components is 100 mol%, the total amount of the segment (A) and the segment (B) is 50 to 70 mol%. preferable. When the total amount of the segment (A) and the segment (B) is out of the above range, any or all of the blocking performance of the ionic substance, the blocking performance of the nonionic substance, and the water permeability. Performance tends to decline.

Further, in the polyamide resin, when the amount of segments derived from all the monomer components is 100 mol%, the total amount of the segment (A) and the segment (C) is 50 to 70 mol%. Is preferable. When the total amount of the segment (A) and the segment (C) is out of the above range, any or all of the blocking performance of the ionic substance, the blocking performance of the nonionic substance, and the water permeability. Performance tends to decline.

The spiral type separation membrane element of the present invention includes the composite semipermeable membrane as a constituent member thereof.

The composite semipermeable membrane of the present invention is excellent in practically well-balanced three performances of blocking performance of ionic substances, blocking performance of nonionic substances, and water permeability. By using the composite semipermeable membrane of the present invention, high-purity water can be efficiently purified from raw water containing an ionic substance and a nonionic substance.

Hereinafter, embodiments of the present invention will be described.

In the composite semipermeable membrane of the present invention, a skin layer containing a polyamide resin is formed on the surface of a porous support. The skin layer is a layer that acts as the main functional layer in filtration.

The polyamide resin is obtained by polymerizing at least a polyfunctional amine component and a polyfunctional acid halide component.

In the present invention, at least m-phenylenediamine and a diamine compound represented by the following general formula (1) are used as the polyfunctional amine component.


(In the formula, either R ¹ or R ² is COOH and the other is hydrogen, and R ³ and R ⁴ are independently hydrogen or alkyl groups having 1 to 4 carbon atoms, respectively.)

It is preferable that R ³ and R ⁴ are independently hydrogen or methyl groups, respectively.

Among the diamine compounds, 3,5-diaminobenzoic acid, 2,4-diaminobenzoic acid, N, N'-dimethyl-3,5-diaminobenzoic acid, and N, N'-dimethyl-2,4-diamino It is preferable to use at least one selected from the group consisting of benzoic acid. Further, it is more preferable to use at least one selected from the group consisting of 3,5-diaminobenzoic acid and 2,4-diaminobenzoic acid.

In the present invention, at least m-phenylenediamine and a diamine compound represented by the following general formula (2) may be used as the polyfunctional amine component.


(In the formula, either R ⁵ or R ⁶ is COOR ⁹ and the other is hydrogen, R ⁹ is an alkyl group having 1 to 4 carbon atoms, and R ⁷ and R ⁸ are independently hydrogen. Or it is an alkyl group having 1 to 4 carbon atoms.)

R ⁹ is preferably a methyl group, and R ⁷ and R ⁸ are preferably independent hydrogen or methyl groups, respectively.

Among the diamine compounds, 3,5-diaminobenzoic acid methyl ester, 2,4-diaminobenzoic acid methyl ester, N, N'-dimethyl-3,5-diaminobenzoic acid methyl ester, and N, N'-dimethyl It is preferable to use at least one selected from the group consisting of −2,4-diaminobenzoic acid methyl ester. Further, it is more preferable to use at least one selected from the group consisting of 3,5-diaminobenzoic acid methyl ester and 2,4-diaminobenzoic acid methyl ester.

Further, in the present invention, at least m-phenylenediamine, a diamine compound represented by the general formula (1), and a diamine compound represented by the general formula (2) are used as the polyfunctional amine component. May be good.

As the polyfunctional amine component, m-phenylenediamine and aromatic, aliphatic or alicyclic polyfunctional amines other than the diamine compound may be used in combination.

Examples of the aromatic polyfunctional amine include p-phenylenediamine, o-phenylenediamine, 1,3,5-triaminobenzene, 1,2,4-triaminobenzene, 2,4-diaminotoluene, 2,6. Examples thereof include -diaminotoluene, N, N'-dimethyl-m-phenylenediamine, 2,4-diaminoanisole, amidol, and xylylenediamine.

Examples of the aliphatic polyfunctional amine include ethylenediamine, propylenediamine, tris (2-aminoethyl) amine, n-phenyl-ethylenediamine and the like.

Examples of the alicyclic polyfunctional amine include 1,3-diaminocyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane, piperazine, 2,5-dimethylpiperazine, 4-aminomethylpiperazine and the like. ..

These polyfunctional amines may be used alone or in combination of two or more. In order to obtain a skin layer with high salt blocking performance, it is preferable to use an aromatic polyfunctional amine.

The polyfunctional acid halide component is a polyfunctional acid halide having two or more reactive carbonyl groups.

Examples of polyfunctional acid halides include aromatic, aliphatic and alicyclic polyfunctional acid halides.

Examples of the aromatic polyfunctional acid halide include trimesic acid trichloride, terephthalic acid dichloride, isophthalic acid dichloride, biphenyldicarboxylic acid dichloride, naphthalenedicarboxylic acid dichloride, benzenetrisulfonic acid trichloride, benzenedisulfonic acid dichloride, and chlorosulfonylbenzenedicarboxylic. Acid dichloride and the like can be mentioned.

Examples of the aliphatic polyfunctional acid halide include propanedicarboxylic acid dichloride, butanedicarboxylic acid dichloride, pentanedicarboxylic acid dichloride, propantricarboxylic acid trichloroide, butanetricarboxylic acid trichloride, pentanetricarboxylic acid trichloride, glutalyl halide, and adipoi. Lehalide and the like can be mentioned.

Examples of the alicyclic polyfunctional acid halide include cyclopropanetricarboxylic acid trichloroide, cyclobutanetetracarboxylic acid tetrachloride, cyclopentanetricarboxylic acid trichloride, cyclopentanetetracarboxylic acid tetrachloride, cyclohexanetricarboxylic acid trichloride, and tetrahydrofuran. Examples thereof include tetracarboxylic acid tetrachloride, cyclopentanedicarboxylic acid dichloride, cyclobutanedicarboxylic acid dichloride, cyclohexanedicarboxylic acid dichloride, tetrahydrofurancarboxylic acid dichloride and the like.

These polyfunctional acid halides may be used alone or in combination of two or more. In order to obtain a skin layer having high salt blocking performance, it is preferable to use an aromatic polyfunctional acid halide. Further, it is preferable to use a trivalent or higher valent polyfunctional acid halide as at least a part of the polyfunctional acid halide component to form a crosslinked structure.

Further, in order to improve the performance of the skin layer containing a polyamide resin, a polymer such as polyvinyl alcohol, polyvinylpyrrolidone or polyacrylic acid, or a polyhydric alcohol such as sorbitol or glycerin may be copolymerized.

The porous support that supports the skin layer is not particularly limited as long as it can support the skin layer, and an ultrafiltration membrane having fine pores having an average pore diameter of about 10 to 500 Å is usually preferably used. Examples of the material for forming the porous support include polysulfone, polyarylether sulfone such as polyethersulfone, polyimide, vinylidene fluoride fluoride, and the like, but particularly chemically, mechanically, and thermally. Polysulfone and polyaryl ether sulfone are preferably used because of their stability. The thickness of such a porous support is usually about 25 to 125 μm, preferably about 40 to 75 μm, but is not necessarily limited to these. The porous support is reinforced by lining with a base material such as a woven fabric or a non-woven fabric.

The method for forming the skin layer containing the polyamide resin on the surface of the porous support is not particularly limited, and any known method can be used. For example, an interfacial condensation method, a phase separation method, a thin film coating method and the like can be mentioned. In the interfacial condensation method, specifically, an amine aqueous solution containing a polyfunctional amine component and an organic solution containing a polyfunctional acid halide component are brought into contact with each other and interfacially polymerized to form a skin layer, and the skin layer is formed. Is placed on the porous support, or a skin layer of a polyamide resin is directly formed on the porous support by the interfacial polymerization on the porous support. Details of the conditions and the like of the interfacial condensation method are described in JP-A-58-24303, JP-A-1-180208, and the like, and those known techniques can be appropriately adopted.

In the present invention, an aqueous solution coating layer composed of an aqueous amine solution containing a polyfunctional amine component is formed on a porous support, and then an organic solution containing a polyfunctional acid halide component is brought into contact with the aqueous solution coating layer for interfacial polymerization. A method of forming a skin layer by allowing the skin layer to be formed is preferable.

In the interfacial polymerization method, the concentration of the polyfunctional amine component in the aqueous amine solution is not particularly limited, but is preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight. When the concentration of the polyfunctional amine component is less than 0.1% by weight, defects such as pinholes are likely to occur in the skin layer, and the salt blocking performance tends to decrease. On the other hand, when the concentration of the polyfunctional amine component exceeds 10% by weight, the polyfunctional amine component easily permeates into the porous support, or the film thickness becomes too thick and the permeation resistance becomes large, so that the permeation flow The bundle tends to drop.

Water is mainly used as the solvent used for the amine aqueous solution, but the diamine compound represented by the general formula (1) or (2) can be easily dissolved to improve the reactivity of the diamine compound. Thereby, in order to increase the content of the segment (B) or the segment (C) derived from the diamine compound in the polyamide resin, it is preferable to use an alcohol in combination. Examples of the alcohol used include methanol, ethanol, isopropyl alcohol and the like. These may be used alone or in combination of two or more. Alcohol is preferably used in an amount of 0.1 to 50% by weight, more preferably 1 to 10% by weight, in the total solvent.

The concentration of the polyfunctional acid halide component in the organic solution is not particularly limited, but is preferably 0.01 to 5% by weight, more preferably 0.05 to 1% by weight. When the concentration of the polyfunctional acid halide component is less than 0.01% by weight, the unreacted polyfunctional amine component tends to remain, or defects such as pinholes are likely to occur in the skin layer, resulting in poor salt blocking performance. Tend to do. On the other hand, when the concentration of the polyfunctional acid halide component exceeds 5% by weight, the unreacted polyfunctional acid halide component tends to remain, or the film thickness becomes too thick and the permeation resistance increases, resulting in a permeation flux. It tends to decrease.

The organic solvent used in the organic solution is not particularly limited as long as it has low solubility in water, does not deteriorate the porous support, and dissolves a polyfunctional acid halide component. For example, cyclohexane, heptane, or octane. , And saturated hydrocarbons such as nonane, halogen-substituted hydrocarbons such as 1,1,2-trichlorotrifluoroethane, and the like. A saturated hydrocarbon or naphthenic solvent having a boiling point of 300 ° C. or lower, more preferably 200 ° C. or lower is preferable. The organic solvent may be used alone or as a mixed solvent of two or more kinds.

Various additives can be added to the amine aqueous solution or the organic solution for the purpose of facilitating film formation and improving the performance of the obtained composite semipermeable membrane. Examples of the additive include surfactants such as sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, and sodium lauryl sulfate, sodium hydroxide for removing hydrogen halide generated by polymerization, trisodium phosphate, and triethylamine. Examples thereof include a basic compound of the above, an acylation catalyst, and a compound having a solubility parameter of 8 to 14 (cal / cm ³ ) ^1/2 described in JP-A-8-224452.

In the present invention, after the contact between the amine aqueous solution and the organic solution, the excess organic solution on the porous support is removed, and the forming film on the porous support is heated to 20 ° C. or higher to form a skin layer. It is preferable to form. By heat-treating the forming film, the reactivity of the diamine compound represented by the general formula (1) or (2) is improved, and the segment (B) or segment derived from the diamine compound in the polyamide resin is improved. The content of (C) can be increased. The heating temperature is more preferably 20 to 200 ° C, still more preferably 100 to 150 ° C, and particularly preferably 130 to 150 ° C.

The polyamide-based resin of the present invention, which is a material for forming a skin layer, has a ratio (mol%) of a segment (A) derived from m-phenylenediamine and a segment (B) derived from the diamine compound in the resin. It is 99.9: 0.1 to 98: 2 (segment (A): segment (B)), preferably 99.8: 0.2 to 98.2: 1.8, and more preferably 99. It is 75: 0.25 to 98.5: 1.5, more preferably 99.7: 0.3 to 98.8: 1.2, and particularly preferably 99.65: 0.35 to 98. 9: 1.1.

The polyamide resin of the present invention, which is a material for forming the skin layer, has a ratio (mol%) of a segment (A) derived from m-phenylenediamine and a segment (C) derived from the diamine compound in the resin. Is 97: 3 to 87:17 (segment (A): segment (C)).

In the polyamide resin of the present invention, when the amount of segments derived from all polyfunctional amine components is 100 mol%, the total amount of the segment (A) and the segment (B) is 50 mol% or more. It is preferably 70 mol% or more, and further preferably 90 mol% or more.

Further, in the polyamide resin of the present invention, when the amount of segments derived from all polyfunctional amine components is 100 mol%, the total amount of the segment (A) and the segment (C) is 50 mol%. The above is preferable, more preferably 70 mol% or more, still more preferably 90 mol% or more.

In the polyamide resin of the present invention, when the amount of segments derived from all the monomer components in the resin is 100 mol%, the total amount of the segment (A) and the segment (B) is 50 to 70 mol. %, More preferably 55 to 65 mol%, still more preferably 56 to 63 mol%, and particularly preferably 56 to 60 mol%. Examples of the segment other than the segment (A) and the segment (B) include a segment derived from m-phenylenediamine and a polyfunctional amine other than the diamine compound, and a segment derived from a polyfunctional acid halide.

Further, in the polyamide resin of the present invention, when the amount of segments derived from all the monomer components in the resin is 100 mol%, the total amount of the segment (A) and the segment (C) is 50 to 50 to It is preferably 70 mol%. Examples of the segment other than the segment (A) and the segment (C) include a segment derived from m-phenylenediamine and a polyfunctional amine other than the diamine compound, and a segment derived from a polyfunctional acid halide.

The thickness of the skin layer formed on the porous support is not particularly limited, but is usually about 0.05 to 2 μm, preferably 0.1 to 1 μm.

The composite semipermeable membrane of the present invention is not limited in its shape. That is, any conceivable film shape such as a flat film shape or a spiral element shape is possible. In addition, various conventionally known treatments may be applied in order to improve the salt blocking property, water permeability, oxidation resistance, etc. of the composite semipermeable membrane.

The spiral type separation membrane element of the present invention can be produced by a known method using the composite semipermeable membrane.

The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

[Evaluation and measurement method]
(Measurement of permeation flux, sodium chloride inhibition rate, and boron inhibition rate)
The prepared flat membrane-like composite semipermeable membrane was cut into a predetermined shape and size and set in a cell for flat membrane evaluation. An aqueous solution containing 3.2% by weight of sodium chloride and 5 ppm of boron (29 ppm of boric acid) and adjusted to pH 6.5 to 7 with NaOH at an operating pressure of 5.5 MPa, a temperature of 25 ° C., and a pH of 6.5. After applying a differential pressure of 5.5 MPa to the supply side and the permeation side of the film at 25 ° C. and contacting the film for 1 hour, the sodium chloride inhibition rate, the boron inhibition rate, and the permeation flux were measured. The sodium chloride blocking rate was measured by ordinary conductivity measurement, and the boron blocking rate was calculated by the following formula from the measurement results obtained by measuring the concentration with an ICP analyzer.
<Sodium chloride inhibition rate>
Blocking rate (%) = (1- (sodium chloride concentration in membrane permeate / sodium chloride concentration in feed solution)) x 100
<Boron blocking rate>
Blocking rate (%) = (1- (boron concentration in membrane permeate / boron concentration in feed solution)) x 100

(Measurement of IPA blocking rate)
The prepared flat membrane-like composite semipermeable membrane was cut into a predetermined shape and size and set in a cell for flat membrane evaluation. Then, at an operating pressure of 1.5 MPa, a temperature of 25 ° C., and a pH of 6.5, a 0.15 wt% isopropyl alcohol (IPA) aqueous solution was permeated through the composite semipermeable membrane for 30 minutes, and then the IPA inhibition rate was measured. did. The IPA inhibition rate was calculated by the following formula from the measurement results obtained by measuring the concentrations of the supply liquid and the permeate liquid with a GC analyzer.
<IPA blocking rate>
Blocking rate (%) = (1- (IPA concentration in membrane permeate / IPA concentration in feed solution)) × 100

(Measurement of the amount of each segment in the polyamide resin)
The prepared composite semipermeable membrane was immersed in cyclohexanone to recover the polyamide resin in the skin layer, collected in a stainless steel tube, added with methanol and alkali, and heated at 240 ° C. for 1 hour to decompose the polyamide resin. .. Then, after allowing to cool to room temperature, the decomposition liquid was recovered and measured in ¹ H-NMR (measuring device: BRUKER Biospin, AVANCE III-600, measuring solvent: DMSO-d6, chemical shift standard: 2.50 ppm (heavy DMSO), 64 total chemical shifts: metaphenylenediamine (7.56 ppm), 3,5-diaminobenzoic acid (7.75 ppm), methyl 3,5-diaminobenzoate (7.78 ppm), trimesic acid chloride (8.60 ppm) ), Isophthalic acid chloride (8.40 ppm)). The segment amount (mol%) was calculated from the peaks derived from each segment component.

Example 1
m-phenylenediamine (MPD) 2.4% by weight, 3,5-diaminobenzoic acid (DABA) 0.9% by weight, sodium dodecylsulfate 0.15% by weight, triethylamine 2.15% by weight, sodium hydroxide 0. An aqueous amine solution containing 31% by weight of camphorsulfonic acid, 6% by weight of camphorsulfonic acid, and 1% by weight of isopropyl alcohol was applied onto the porous polysulfone support, and then the excess amine aqueous solution was removed to form an aqueous solution coating layer. .. The content ratio of MPD and DABA in the amine aqueous solution is about 80 mol% of MPD and about 20 mol% of DABA. Next, 0.075% by weight of trimesic acid chloride (TMC) and 0.113% by weight of isophthalic acid chloride (IPC) were dissolved in a naphthenic solvent (Exxsol D40, manufactured by ExxonMobil) on the surface of the aqueous solution coating layer. Soaked in the allowed acid chloride solution for 7 seconds. Then, the excess solution on the surface of the aqueous solution coating layer is removed, air-dried for 20 seconds, and further held in a hot air dryer at 140 ° C. for 3 minutes to form a skin layer containing a polyamide resin on a porous polysulfone support. It was formed to prepare a composite semipermeable membrane.

Example 2
m-phenylenediamine (MPD) 2.1% by weight, 3,5-diaminobenzoic acid (DABA) 1.3% by weight, sodium dodecylsulfate 0.15% by weight, triethylamine 2.15% by weight, sodium hydroxide 0. A composite translucent film was prepared in the same manner as in Example 1 except that an amine aqueous solution containing 31% by weight, 6% by weight of camphorsulfonic acid, and 1% by weight of isopropyl alcohol was used. The content ratio of MPD and DABA in the amine aqueous solution is about 70 mol% of MPD and about 30 mol% of DABA.

Example 3
m-phenylenediamine (MPD) 1.5% by weight, 3,5-diaminobenzoic acid (DABA) 2.1% by weight, sodium dodecylsulfate 0.15% by weight, triethylamine 2.15% by weight, sodium hydroxide 0. A composite translucent film was prepared in the same manner as in Example 1 except that an amine aqueous solution containing 31% by weight, 6% by weight of camphorsulfonic acid, and 1% by weight of isopropyl alcohol was used. The content ratio of MPD and DABA in the amine aqueous solution is about 50 mol% of MPD and about 50 mol% of DABA.

Example 4
2.7% by weight of m-phenylenediamine (MPD), 0.45% by weight of 3,5-diaminobenzoic acid methyl ester (DABAME), 0.15% by weight of sodium dodecyl sulfate, 2.15% by weight of triethylamine, sodium hydroxide A composite translucent film was prepared in the same manner as in Example 1 except that an aqueous amine solution containing 0.31% by weight, 6% by weight of camphorsulfonic acid, and 1% by weight of isopropyl alcohol was used. The content ratio of MPD and DABAME in the amine aqueous solution is about 90 mol% of MPD and about 10 mol% of DABAME.

Comparative Examples 1 and 2
A composite semipermeable membrane was prepared in the same manner as in Example 1 except that the formulation was changed to that shown in Table 1.

The composite semipermeable membrane and spiral separation membrane elements of the present invention are suitable for the production of ultrapure water, desalination of brackish water or seawater, and stains that cause pollution such as dyed wastewater and electrodeposited paint wastewater. Therefore, it is possible to remove and recover the pollutants or active substances contained in the wastewater and contribute to the closure of wastewater. In addition, it can be used for advanced treatment such as concentration of active ingredients in food applications and removal of harmful components in water purification and sewage applications. It can also be used for wastewater treatment in oil fields and shale gas fields.

Claims (7)

In a composite semipermeable membrane in which a skin layer containing a polyamide resin is formed on the surface of a porous support,
The polyamide-based resin is obtained by polymerizing a polyfunctional acid halide component and a polyfunctional amine component, and the polyfunctional amine component is m-phenylenediamine and at least one of the following general formulas (1). Including the diamine compound represented by
The ratio (mol%) of the segment (A) derived from m-phenylenediamine and the segment (B) derived from the diamine compound in the polyamide resin is 99.9: 0.1 to 98: 2 ( A composite semipermeable membrane characterized by being a segment (A): a segment (B)).
(In the formula, either R ¹ or R ² is COOH and the other is hydrogen, and R ³ and R ⁴ are independently hydrogen or alkyl groups having 1 to 4 carbon atoms, respectively.) The composite according to claim 1, wherein the total amount of the segment (A) and the segment (B) is 50 mol% or more, assuming that the amount of the segment derived from all the polyfunctional amine components is 100 mol%. Semipermeable membrane. Claim that the total amount of the segment (A) and the segment (B) is 50 to 70 mol% when the amount of the segment derived from all the monomer components in the polyamide resin is 100 mol%. The composite semipermeable membrane according to 1 or 2. In a composite semipermeable membrane in which a skin layer containing a polyamide resin is formed on the surface of a porous support,
The polyamide resin is obtained by polymerizing a polyfunctional acid halide component and a polyfunctional amine component, and the polyfunctional amine component is m-phenylenediamine and at least one of the following general formulas (2). Including the diamine compound represented by
The ratio (mol%) of the segment (A) derived from m-phenylenediamine to the segment (C) derived from the diamine compound in the polyamide resin is 97: 3 to 83:17 (segment (A)). : A composite semipermeable membrane characterized by being a segment (C)).
(In the formula, either R ⁵ or R ⁶ is COOR ⁹ and the other is hydrogen, R ⁹ is an alkyl group having 1 to 4 carbon atoms, and R ⁷ and R ⁸ are independently hydrogen. Or it is an alkyl group having 1 to 4 carbon atoms.) The composite according to claim 4, wherein the total amount of the segment (A) and the segment (C) is 50 mol% or more, assuming that the amount of the segment derived from all the polyfunctional amine components is 100 mol%. Semipermeable membrane. Claim that the total amount of the segment (A) and the segment (C) is 50 to 70 mol% when the amount of the segment derived from all the monomer components in the polyamide resin is 100 mol%. The composite semipermeable membrane according to 4 or 5. A spiral separation membrane element comprising the composite semipermeable membrane according to any one of claims 1 to 6.